Wonnald. — ‘ Brown Rot ’ Diseases of Fruit Trees. 397 
Again observations on the sixth day after inoculation showed that 
infection of the styles had occurred. As before, one inoculated flower 
developed into fruit ; the rest all became withered and fell off. 
The results of these four experiments, together with those obtained in 
the experiment carried out in 1917, may be summarized as follows : 
Results of Inoculations made on Apple Flowers with 
Strains of Monilia cinerea. 
No. of 
flowers 
inoculated. 
No. of spurs on 
which the in- 
oculated flowers 
were situated. 
No. of 
spurs 
killed. 
No. of inoculated 
flowers which 
developed into 
fruit. 
‘ Blossom Wilt 
1918 
Ax 
6 
3 
3 
0 
and Canker ’ 
a 2 
10 
5 
4 
0 
strains of Monilia 
a 3 
6 
3 
2 
0 
cinerea from ap- 
ple trees 
B 
6 
3 
2 
1 
I 9 I 7 
A 2 
4 
4 
4 
0 
Total . 
32 
18 
L 5 
1 
Other strains of 
1918 
Plum 
10 
5 
0 
1 
M. cinerea from 
various sources 
Cherry 
‘ Wither 
10 
5 
0 
0 
Tip’ of 
plum 
10 
5 
0 
1 
Pyrns 
japonic a 
8 
4 
0 
0 
- 
1917 
‘ Wither 
Tip ’ of 
plum 
10 
4 
0 
0 
Total . 
48 
23 
0 
2 
Thus of the 18 spurs bearing flowers which had been inoculated with 
the strains from apple trees, 15 were killed outright, with all their flowers 
and leaves, while the inoculation of 48 flowers with strains from sources 
other than the apple did not produce in any one instance infection of the 
tissues of the spur, although there was evidence that infection of the flowers 
actually inoculated had occurred. 
The conclusion is, that the ‘Blossom Wilt and Canker Disease’ of 
apple trees is caused by a specialized form of Monilia cinerea. 
Woronin ( 1900 ) stated, as a result of his own inoculation experiments 
on apple flowers, that M. cinerea was unable to produce a Blossom Wilt of 
apple trees. The host from which he obtained the strain used in his 
experiments is not stated, but in all probability it was a cherry or plum ; 
had he worked with a strain taken from a dead spur or canker of an apple 
tree he might have obtained a different result. 
VI. Conclusions. 
A general discussion of the results recorded in the present article is 
reserved for a future occasion, when they will be correlated with those of 
F f 2 
